Well it sure as hell ain't found in the Palestinians. There are types of this gene that only Jews have the most of, and the others that also have it are in lands that Jews used to live in and migrated out of, ie Kurds, Iraq, (I have relatives that are Iraqi / Kurdish Jews) so it's certainly plausible that this gene exists in those populations.
Yes, it is:
Jews, Palestinians have close genetic ties, say researchers - Beliefnet News
Ariella Oppenheim Ph.D., a researcher at Hebrew University and the Hadassah Medical School labs, has published the result of DNA studies which show that both the Palestinians and Jews are descended from the Kurds of Iraq and Turkey.
That should astonish no one since both the Bible and the Koran say the Jews and Arabs are descended from a common ancestor, an ancient Caldean who the Koran calls Ibrahim. The Bible says he was named Abraham.
Perhaps more surprising, Oppenheim found the Ashkenazi Jews from Europe are genetically closer to the Palestinians than Middle East Jews.
Oppenheim also isolated and traced the chromosome for the “priestly” Cohen line.
“We find that Arabs also carry this chromosome,” she noted in a documentary film, which claims that some Palestinians are also Cohens, genetically.
Also:
Jews Are The Genetic Brothers Of Palestinians, Syrians, And Lebanese
The study, published in the May 9 issue of the Proceedings of the National Academy of Sciences, found that Jewish men shared a common set of genetic signatures with non-Jews from the Middle East, including Palestinians, Syrians, and Lebanese, and these signatures diverged significantly from non-Jewish men outside of this region. Consequently, Jews and Arabs share a common ancestor and are more closely related to one another than to non-Jews from other areas of the world.
As I said the Palestinians are exactly the same as the neighboring Arabs such as the Syrians, Jordanians, and Egyptians. And clearly today's Jews are a different people. They are as related to the Palestinians as they would be to Egyptians or Jordanians.
That isn't supported by genetic research. Differences appear very minor with considerable overlap among the different groups. I think you need to give up on that line of argument as a justification for any sort of special considerations. They're effectively the same people, with long standing ties to that region. Neither side can claim any "special connection" or claim to be indiginous where the other is not.